While in vivo methods have proven invaluable in determining the physiological characteristics of human disease, progress in understanding rodent models has been delayed due to the lack of methods. Rapid progress in miniaturization, and in the increased sensitivity of monitoring devices has provided tools that can access information from relatively undisturbed rodents. The Animal Physiology Core (APC) brings together four experts in the areas of integrative physiology, cardiovascular physiology, imaging, and animal models to serve as a core resource for the study of diabetes. The goal of the APC is to facilitate and enhance the combined metabolic and vascular phenotyping of small animals by providing easy access to highly-specialized equipment and expertise in the areas of body composition, energetics, glucose homeostasis, cardiovascular assessment, molecular imaging, and transgenic animal models. This will enhance the capability and cost-effectiveness for DRTC members in the use of small animals for studying diabetes, diabetes complications, and cardiometabolic disease. The specific aims of the Core are to provide the following: 1 Body composition: Whole-body composition analysis by chemical carcass analysis, dual-energy X-ray absorptiometry (DXA), quantitative magnetic resonance (QMR), and micro-computed tomography. 2 Energy balance: Comprehensive assessments of metabolic rate (indirect calorimetry), food intake, fecal output, activity, and body temperature. 3 Glucose homeostasis: Glucose and insulin tolerance testing and hyperinsulinemic clamps. 4 Cardiovascular assessment: Echocardiography and myocardial function, vascular compliance, and blood pressure. 5 Metabolic/Molecular Imaging: Bioluminescence, fluorescence, and gamma-ray imaging, including SPECT/CT. 6 Transgenic animal models: Assistance with construct preparation, generation of transgenic/knock-out mice, husbandry and colony management, and genotyping. These services are based upon the expressed needs of DRTC investigators, and will incorporate expertise and current technology for both metabolism and vascular assessment, brought together in one core for combined applications by the user base. This will facilitate a more sophisticated, multidisciplinary,and comprehensive approach to diabetes research, and provide common ground for collaboration